Washington County is a Republican stronghold. About 23% of voters here vote Democratic and 77% Republican.
About 82% of adults in Washington County typically vote, above the U.S. average of about 62%. Among adults in Washington County, ~19% vote Democratic, ~63% Republican, and ~18% don't vote. The map below shows estimated turnout by block group.
How Washington County compares
Among counties within 50 miles, Washington County leans more Republican than 13 of 15 neighbors.
Washington County runs about 64 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Washington County is one of the few Republican-leaning pockets.
Politics vary noticeably by city within Washington County. The east side is the most Republican-leaning (R+64) and the south side is the least Republican-leaning (R+51), a spread of about 13 points.
Why Washington County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Washington County, not a ranked or complete list of what matters most.
Washington County votes against the grain of Illinois. Illinois leans Democratic overall, while Washington County runs about 64 points more Republican. Car-dependent areas vote Republican, and about 83% of residents in Washington County drive to work alone, above 86% of counties.
Walkability and Republican lean
Places with a low walkability score tend to lean Republican; Washington County, IL sits in the bottom quarter nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Washington County looks the way it does
Homeowners vote more often than renters. About 84% of households in Washington County own their home, about 9 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Clinton County, IL R+47
- Perry County, IL R+49
- Marion County, IL R+47
- Jefferson County, IL R+44
- Randolph County, IL R+45
- St. Clair County, IL D+13
- Bond County, IL R+39
- Franklin County, IL R+52
- Monroe County, IL R+39
- Jackson County, IL D+7
Counties with Similar Populations
- Winn Parish, LA R+44
- Converse County, WY R+66
- Glacier County, MT D+32
- Morgan County, KY R+64
- Morgan County, OH R+55
- Breathitt County, KY R+62
- Chowan County, NC R+12
- Callahan County, TX R+69
- Newton County, IN R+54
- Madison County, VA R+34
Sources and methodology
Precinct-level voting records used to fit the model come from Illinois State Board of Elections, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.